Losing 10 degrees over 45 min

[Brewklyn]

Hi All,

I just converted a 5 gallon igloo cooler to a mash tun. I plan on doing a partial mash Alakan Smoked porter clone. The kit i received has a total of 3.5 lbs of grain. I estimatedIi should be using about 5.25 quarts of water. was I did a few tests to see if it would hold temp and put 5.25 quarts in at about 160 degrees. I covered the top with some towles and also filled the cover with foam insulation. I came back after 45 min and took the temp and it dropped 10 degrees to 150.

I'm thinking that it might be because I am just using water and no grain or becuase i have so much headspace in a 5 gallon cooler with only 5.25 quarts of water. Any thoughts or suggetions ?

Also, i put a bazooka screen inside the cooler but it doesn't lay flat across the bottom. it is about a half inch off the bottom where the spigot would be, is that ok or does it need to lay across the bottom?

Thanks

 

[Denny's Evil Concoctions]

Did you preheat the cooler? A cold cooler will make that temp drop quicker.

 

[brrman]

I think Denny's got it... The cooler will kill 5-10 degrees to warm up to the temp of the water.

 

[Brewklyn]

i did fill the cooler about half way with some hot tap water but did not heat the water on the stove or anything like that. I guess that will be my next test.

 

[Wade E]

The screen will need to lay on the bottom or you are going to have to adjust for that loss and you may not get all the sugars, if you can bend it or throw in a slight elbow youd be way better off then adjusting for that loss. That head space will also contribute to some heat loss but not that much. When you heat up your mash in water heat up some extra to allow for cooler pre strike. You will also want to start off with a higher temp on your strike water for grain heat absorption.

 

[Brewklyn]

cool. But even if i made a bend in the screen and the screen was on the bottom, i don't undedrstand how more liquid would be able to get out becase the spigot hole is still a half inch off the bottom.

 

[bull8042]

I would always overshoot my strike temp by 5 - 6 deg and stir after adding until it dropped to temp. This would preheat the cooler I was using and allow me to nail my strike temp.
With regards to your test, I did the exact same thing when I first started with a cooler and had the same results. You will find a HUGE difference when you add the mass of the grain bill in there. The temp will remain much more steady.

 

[Wade E]

Its not the spigot hole that makes the difference, its how low the manifold is and how high you are from the next vessel for gravity to create a siphon. The lower the manifold is in the cooler the more wort youll be able to pull out of the cooler before air breaks the siphon.

 

[david_42]

Try using a 4:1 or even 5:1 ratio. More water will keep the temperature up.

Also, nothing says you can't tilt the cooler to drain the last of the wort.